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Determination of Oleyl Propylenediamine, a Commonly Used Film Forming Amine, on the Surfaces of Water-Steam Cycles
Organic cycle chemistry based on oleyl propylenediamine (OLDA), a commonly used film forming amine (FFA), provides an excellent treatment option for water-steam
cycles, especially for plants operating in cycling mode where preservation is required during shutdowns but unit availability must be maintained. Uniper has
successfully trialled this treatment in the triple-pressure combined cycle gas turbine (CCGT) power plant at Connah's Quay, United Kingdom.
During a trial phase over almost three years at Connah's Quay, a comprehensive monitoring and control program was carried out. This paper reports the results of
studies to determine the presence of OLDA on the surfaces of the watersteam cycles in two units. These included inspections of the heat recovery steam generator
(HRSG) drums and low-pressure steam turbines during plant outages and, additionally, the sampling and off-site analysis of boiler tubes taken from the high-pressure
evaporator and reheater circuits. A study on superheater tubes from a pilot boiler at the Kurita Global Technology Center in Japan complemented the field results.
Three different methods of analysis were applied: the non-specific hydrophobicity or droplet test using a spray of demineralised water, Kurita's own newly developed
surface wipe test specific for OLDA, and x-ray photoelectron spectroscopy to check for amine nitrogen on material surfaces. The first two tests were carried out
on-site, the third one off-site.
OLDA could be detected on the surfaces of all investigated components of the water-steam cycles from both units at Connah's Quay. This included components operated
not only under wet conditions, but also under dry conditions. The film forming amine was also detected on the superheater tubes from the pilot boiler treated with
FFA-based cycle chemistry. The film forming amine could not be measured on surfaces which had not been exposed to a cycle chemistry with FFAs.
The OLDA film was present on all surfaces of the water-steam cycle in components that were examined in the Connah's Quay units. A key operational control was to
ensure that a small residual FFA concentration was analytically detected in the condensate before unit shutdown. This finding supports the practical approach for
the control of FFA-based cycle chemistry, where the analytical proof of FFA in the condensate indicates complete film formation in the water-steam cycle. The
Kurita wipe test is an easy tool to apply which enables operators to verify complete film formation by the specific measurement of OLDA on water-steam cycle surfaces
during plant inspections.
The results strongly indicated that OLDA is present on surfaces throughout the complete water-steam cycle in both water circuits and in dry steam stages. Therefore,
the technology has the capability to protect all components in watersteam cycles if the FFA is applied correctly.
PowerPlant Chemistry 2017, 19(3), 129–140
Cleanup of the Closed Cooling Water System at AES Alamitos Units 5 and 6
Early in 2016 it was discovered that the closed cooling water system at AES Alamitos Units 5 and 6 was severely fouled with bacteria slime. The buildup of slime
occurred over time due to the chemical addition of nitrite-based corrosion inhibitor, inadequate monitoring, and an absence of biocide treatment. The fouling
resulted in unit load restrictions due to cooling water temperatures becoming too hot. This paper describes the system cleanup and its restoration to normal
PowerPlant Chemistry 2017, 19(3), 142–148
Corrosion Product Sampling and Analysis – The Distribution behind the Results
In relation to the ongoing revision of the International Association for the Properties of Water and Steam (IAPWS) Technical Guidance Document (TGD) on Corrosion
Product Sampling and Analysis a field trial has been conducted. These first parallel measurements have given consistent results indicating that the content of
corrosion products in a series of samples is distributed according to the log-normal distribution function. This matches observations over the last few years
for samples acquired over both short and longer periods. Working under the basic assumption that corrosion product results are log-normally distributed alleviates
the problem often encountered in practice of obtaining 10–20 % high, outlying results in a series of samples. Two statistical figures characterise the
distribution of results: the median and the 95th percentile. Both are easy to understand, interpret and communicate; thus, they are well suited as convenient
routine quality parameters.
This paper summarises the results of the field trial and gives examples of log-normally distributed corrosion product data covering periods of a couple of years.
PowerPlant Chemistry 2017, 19(3), 154–163
Ion Exchange Challenges in a Dairy Product Processing Factory Cogeneration Plant
This paper outlines the challenges of an ion exchange plant used to produce high-quality make-up water for heat recovery steam generators producing steam for
use in both dairy food processing and electricity production via a steam turbine at a large dairy factory in New Zealand.
It discusses the processes that site management and operators went through to improve the plant's reliability and water quality. These included the identification
of key problem areas, changes to the ion exchange plant operation and maintenance, investigation into measurement of the dairy factory condensate return quality,
the implementation of a performance management program for the plant, and training of the key personnel.
PowerPlant Chemistry 2017, 19(3), 164–173
Report on the International Conference on Film Forming Amines and Products in Lucerne, Switzerland
The first International Conference on Film Forming Amines and Products was held in Lucerne, Switzerland, on April 3–6, 2017. The conference was organized
by the International Association for the Properties of Water and Steam (IAPWS) with the support of the Swiss Committee for the Properties of Water and Steam (SCPWS).
The main purpose of this conference was to advance the knowledge about film forming amines and products, including the latest science. Scientific papers and case
studies provided excellent insights into the most recent developments in this field of cycle chemistry, and numerous examples of the application of film forming
amines and products in fossil, combined cycle, nuclear, and other plants were given during the three-day conference.
A short summary of the conference events is given in this report.
PowerPlant Chemistry 2017, 19(3), 174–178